If you shoot with a Canon 5D Mark II or 60D and want to unlock new functionality for your camera, Magic Lantern's latest v2.3 is now available as a free download.
"Magic Lantern v2.3 represents an important milestone - professionals from all around the world are already trusting it for their paid work. We can safely say it's no longer a hack, but it's strongly heading towards a solid piece of engineering that you can trust". New or improved features: